MAP21: Pitfalls (Doom 64)

MAP21: Pitfalls is the twenty-first level of Doom 64, designed by Tim Heydelaar. This is one of the darker levels of the game, with the eerie music track "Perfect Hate" characterized by deep howling, high-pitched orchestral music, and insect buzzing and a dark, scary atmosphere.

Walkthrough
The first part of the level is suggested in the name, as there is a great cave with a huge pit of lava in the middle. The player has to find their way over the pitfalls while battling imps and cacodemons. The second part of the level consists of dark hallways with strange rooms, ending up with a bigger shrine-like room where a skull key may be found. Going back and forth through this level is only made worse by monsters jumping out at you in the hallways, and new sections in the caves opening, releasing new waves of monsters. To exit the level, a multi-colored gate in the hallways must be opened and the player has to jump down one last pitfall.

Secrets

 * 1) In the lava pit there should be a couple of radiation suits and you can find a rock shaped as an arrow pointing to a narrow corridor leading to an elevator.  Take this elevator up to collect some goodies.
 * 2) At the western set of four torches/pillars, there will be the rock staircase that will need to have been opened to progress through the level.  Follow these stairs up and continue to follow or hug the wall on your left-hand side till you find yourself on a narrow ledge.  Run forward off this ledge to an opening to a drop-off that will have some items to collect.  You can safely leave this spot by jumping off directly onto a teleporter below in the lava pit.
 * 3) Immediately after teleporting to the second section of the map (maze-like), travelling left will bring you to a hallway with two short dead-end hallways.  In the middle of this hallway the southeastern wall can be lowered to reveal rockets, health and a lurking enemy.
 * 4) In the maze-like second section of the map is yet another secret in the vicinity near secret #3.  To access this secret, take the hallway between secret #3 and the blue-key door until you get to a set of blocks with faces on both sides.  One of these faces will have its eyes lit up red.  Shoot this face and make your way back up the hallway and a wall with a decoration will have lowered revealing a Mega-Armor.